This class name is confusing: usually classes are not named as singular nouns, not plurals.

* Since you're subclassing `ModuleStoreTestCase`, this is a kind of test case.  So the name should have `TestCase` in it somewhere, or at least `Test`.

* The fact that this is uses a Mongo modulestore is an implementation detail -- the test logic should work regardless of how courses are stored.  So the name shouldn't include `Mongo` (although it might include `Modulestore`).

I'd recommend renaming it to: `LoginTestCase` or `LoginTestCaseMixin` (to emphasize the use of a mixin design pattern)